Generate file attachment transactions for explicit Remarkup attachments on common edit pathways
Ref T13603. On common edit pathways, extract explicit file attachments from Remarkup. These pathways are affected:
- Objects that use EditEngine and expose a remarkup area via "RemarkupEditField".
- Objects that use EditEngine to generate a comment area.
This is the vast majority of pathways, but not entirely exhaustive.
Test Plan: Created and commented on a task, explicitly attaching images. Saw images attach properly.
Maniphest Tasks: T13603
Differential Revision: https://secure.phabricator.com/D21830